1. Field of the Invention
The present invention relates to a drive unit for doors, especially doors having a non-rectilinear profile.
More particularly, the present invention relates to a drive unit for elevator doors having a semicircular profile.
2. Description of Related Art
As is known, elevator systems comprise cars of various type, mainly of parallelepiped form with a square or quadrangular plan. In these cases, the doors that close the car room slide rectilinearly along special guides.
Circular plan cars are also common in civil and commercial buildings, and are utilized both for elevators and to create access zones to buildings such as, for instance, banks, hotels and public facilities.
Obviously, the doors of these cars have a profile that is not rectilinear but semicircular or, more precisely, circle-arch shaped. The cars of this type have severe drawbacks as concerns the opening and closing movements of the related doors. In fact, the motor units must comprise connections able to transform the rectilinear motion into a motion developed along circle-arches parallel to the profile of the car.
The traditional solutions adopted to this aim are extremely complicated from both the construction and the functional aspects, because of the presence of a high number of components, such as, for instance, articulated arms, tie-rods and transmissions.
As a consequence, also maintenance and repair operations of the apparatus intended for door movement are exacting, difficult and sometimes critical.
A further drawback which is found in circular plan cars is associated to the big size and weight of the drive unit of the door, independently on whether it is located on the roof or the base of the car.
There are, in fact, necessary specific reinforcement and supporting structures that concur to further complicate the construction and the assembly of the system.
The presence of many linkages and transmissions gives also rise to a high friction between the moving parts, requiring the use of high power motive units, with an ensuing increase in energy consumption.
Object of the present invention is to obviate the above drawbacks.
More particularly, object of the present invention is to provide a drive unit for doors having a non rectilinear profile, in particular and especially elevator doors with a circular plan such as not to require the use of many elements interconnected with each other to cause such movement.
A further object of the invention is to provide a drive unit as defined above, extremely compact, of a limited weight and suitable to be connected in a quick and easy manner to the roof or the base of the car.
A further object of the present invention is to provide a movement group that does not involve maintenance interventions.
A further object of the invention is to provide a drive unit wherein the friction between the components is extremely reduced.
A further object of the invention is to provide a drive unit for doors having a rectilinear profile, suitable to ensure a high level of resistance and reliability in the time, and also such as to be easily and economically realized.
These and still other objects are achieved by the drive unit for doors having a non-rectilinear profile, in particular for doors of circular plan elevator cars, constituted of aligned or telescopically moving superposed wings, characterized basically in that it comprises a motor provided with a shaft that rotates in alternate clockwise and anti-clockwise direction, and at least a bar or section connected to at least one of the wings and that engages with said shaft.
Said drive unit may be located on the roof or the lower base or between the wings of the elevator cars of story doors.
In the case of doors constituted of telescopic movement superposed wings, the bar or section is connected to one only of the wings, and a transmission unit transmits the rotation of said wing to the other wing of the door.